Fishway



l-l. A. MIDDAUGH l FIsHwAY Filed July v, 1924 2 sheets-smet 1 Horace AlN/ddaughf Feb. 3. 192.5.

Ill. ls Y Feb. 3. l 925.

H. A. MIDDAUGH FISHWAY 'Filed July '7, 1924 2 Sheets-Sheet 2 Patented Feb. 3, 1925.

UNITED ASTATES HORACE A. MIDDAUGH, OF SEATTLE, WASHINGTON. y y

FISHWAY.

Application led July 7, 1924. Serial No. 724,564.

To all whom t may conce/m.'

Be it known that I, HORACE A. MIDDAUGH,

a citizen of the United States of America, and resident of the city of Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Fishways, of which the following is a specification.

My invention relates to fishways or devices by which fish are enabled to overcome elevations produced by dams, falls, and the like, in streams.

y The object of' my invention is to produce a more eicient device than those already in use, and one which will enable the fish to overcome falls and dams of greater altitude than those which they` have been able to sui-mount by previously existing devices.

My invention consists in the provision'of a series of pools connected by short falls and a provision whereby the device may be made easily adapted for use with a considerable variation in the surface'elevation of the reservoirs or poo-ls at the upper end of the dam or fall. Y

Other objects of my invention may be ascertained by a study of the following specilication and reference to the drawings.

Figure 1 is a sectional elevation taken lengthwise of my device, which direction would ordinarily be transverse the dam or in a direction extending up and down the stream.

Figure 2 is a plan view of a fish way embodying my invention.

Figure 3 is an elevation showing a section of the fishway at its upper end.

Figure 4 is a transverse section showing the upper end of the iishway and the manner of providing adjustable exits for the fish into the pool.

It is a peculiarity of anadromous fish to persistently swim up stream during the spawning season. This causes them at all times to swim against the current. Therefore, to make anyflshway or sh ladder effective for such fish, it is necessary to have the entrance thereto located at the highest point of the stream accessib-le to the iish betore meeting the obstruction. Having this in mind I locate the ent-*rance rto my fishway at the face of the dam or falls, or as near thereto as possible. It would, in effect, be desirable, if this were possible, to locate the entrance in a slight bay extending into the dan.

In the drawings, 6 represents the wall of a dam. In this a slight bay 1 is shown in which is located the lower end of the lishway. In the fishway are formed a series of pools 11 by means of transverse walls 12. Preferably these walls are provided near one end with a section 13 which is slightly lowered in height as compared with the remainder. Such a sufficient amount of water flowing down the fishway, water may flow over the more elevated portion of the wall 12, but when the flow of-water is limited i-tV may be entirely confined to the short section 13.

lhe difference in elevation between the successive pools may be made whatever experience shows will beeasily overcome by` the fish. The Vsize of the pools is such that the fiow of walter therein is very slight, thus providing resting places for the fish preced ing their leap to the next pool above.

In the above -respectmy fishway in a general way resembles fishways which have been previously proposed. It however differs from other fishways in having its entrance located either at or slightly above the lower face of the dam, thus greatly increasing the probabilities that the fish will find the entrance. Anadromous fish, in ascending a stream and coming to adam or fall, will collect in the pool below the dam and will swim back and forth across the river, hunting for a place where their ascent can be continued. In doing this they will enter the bay in the dam and, finding quiet water, will eventually find the slight fall pouring over the gap 13 in the lowermost transverse wall of the fishway. Thev will be enabled to leap from the pool at the base of the fishway into the iish pool 11, and lfrom this, in succession, into the pools above. The lish may rest in any of these pools before leaping into the next. l

To make a fishway thoroughly practical for all conditions, it must be so designed that it will accommodate itself to variations in level of the water in the reservoir or pool above the dam or fall. In consequence I have providedy means whereby the fish may pass from any one of several pools located at the upper end of the fishway. into the body of water above the dam. To this end I have provided tunnels 2, extending from each of several of the uppermost pools to and opening into the pool above the dam. I have also provided gates, as 3, which may be opened or closeda-t will so that the-'upper outletofthese tunnelsmay be closed when desired.

It is the intention that the gates covering the outlets of these tunnels'will be closed eX- ceptng` for one, or possibly two, of thoseA which are nearest to the surface of the Water `in the pool above the dam; The outlet 2() from the tunnel 2 into the` pool above the damgeis preferably'made'much smaller iin cross section#thanA tl'1e=cross section of the maiirtunllfiel.'r The flow ofx'vaterin the tunneltproper is ftlinsy reduced" considerably and l asfaslight doviiivarrdho'w"'is maintained therein, the natural tendencyfof the fish-Ito swim against' thecurrent causesit toenter thetunnel and swim to its'upper'end. This'V it'ca'n fdo Without materially exerting itself.

lien, however, it reachesfthe upper end-it must make a slight spurt to 'passthrough the opening Q0. v

Asy the vWater in the pooh-above theol-dam lowers, the gates 3 are opened in succession so as'toikeep at leastonmand possiblyltwo, open atall 'times;= To `prevent debris from rblockingrthe entrances "20', gratings consisting"ofY haist and .LOf'are placed in front of this 'entrances The loWer Iside of thisl'grating" underthe grating.

rIliefsidevWallsy60 of the ishw'ay may beY and 'having sinlets-i cominnieati of 'the grated 1 areal solthatthe fish, afterfpassing through the`open'1ngw20,fmay swim downward'and'y made oit vWha-teven size andwveightf' lis necessary to restrain the pressure "ofl the 4Water above the dam. A suitable location for such a iishway would often place it at the end of the dam, in which case it might be located in a cut-in the bank. The location of the fish- Way is immaterial except that it must comply with 'thefrequirenents iirst mentioned, that its entrance is at the lower face olf the dam.

lVhat'I c'laim as invention is t 1g .A shv'vayhavng :l a y"sei-less of stepped pools, ftuniels' flleadingf- 'from2 certain i of the u pl'Jeri'iiostff l pools tofA inlets communi catino` with Y tl'ieE poolf above th'efdan or tally 1 anc meansffo'r 'closing'fsuch'othe inlets as de= sired.

21A shwayrhaving steppedffpols,tunnels leading3 vfromfcertviii" 'ofthe uppermost' pools with' fthe pool above the fishway, said inl being of much smaller!"y areatl'i'ani' that of the l' tunnels, and rneans'loi*"closingv sardi nletsias desired.

2%, A shvay-comprising-Ja I seriesof stepped pools, V'thel walls v`-bet'weefr'r thepools having"Y over-Hoi alternately" at lopposite sidesffoif the is'hwa-.g certaini ot'the 'upper poolsV havingl tunnelslc inluni'cating with the `pool'a'b'ove''lth'eiis ay at levels corresponding with the-levell of vlsaid pools and by openings' of reduced area compared ywith the area of the tunnels; andi lmea's" for` 'closing said inlet openings'atWilli HORACE' iA.: MDDAUGH. 

